Age-related macular degeneration (AMD) is a disease of the retina, the back layer of the eye, which sends images to the brain.
There are two types of AMD: dry AMD and wet AMD.
Age-related macular degeneration (AMD) is a disease of the retina, the back layer of the eye, which sends images to the brain. There are two types of AMD: dry AMD and wet AMD.
Dry AMD occurs due to deposits that form under the retina called drusen. The progressive accumulation of drusen causes the central vision to become distorted or degraded slowly. Wet AMD occurs when abnormal blood vessels grow under the retina and leak or bleed, causing a rapid decline in central vision.
There are three stages of AMD:
- Early AMD: This stage has small or a few intermediate-sized drusen and usually has no associated vision loss.
- Intermediate AMD: People with intermediate AMD have multiple medium-sized drusen or some large drusen.
- Advanced AMD: This refers to either the most severe form of dry AMD, called geographic atrophy (areas of the retina are damaged enough that they’re no longer working), or wet AMD.
Unlike dry AMD, wet AMD can progress quickly if not treated. Dry AMD typically progresses slowly over a period of many years, and any associated vision loss is gradual.
When it converts to wet AMD, vision loss can occur quickly, within days to weeks. If wet AMD isn’t treated, the central vision will continue to deteriorate rapidly in most cases.
AMD is a progressive condition. Treatment can slow or reverse vision loss associated with wet AMD in some cases. But without treatment, the condition will progress to significant central vision loss.
Not all people with wet AMD will lose enough vision to be considered legally blind. However, blindness is much more common with wet AMD than with dry AMD.
Only 15% to 20% of people with AMD have the wet type, but they account for 80% of people who are blind from AMD.
It’s crucial to note that AMD doesn’t affect peripheral vision. So, people living with the condition may become legally blind from a loss of central vision but will not lose all their vision.
Currently, there’s no cure for AMD. But a specific combination of vitamins known as
Once wet AMD has developed, the most common treatment involves injections of a medication called anti-VEGF into the eye. Anti-VEGF injections eliminate the abnormal blood vessels that cause the wet form of macular degeneration.
The injections can decrease swelling in the retina and reverse some vision loss. More often, the injections are used to prevent further vision loss. Most people will need to repeat these injections regularly to keep their wet AMD under control.
There are several risk factors for AMD. These include:
- heart disease
- high blood pressure
- high cholesterol
- overweight or obesity
Quitting smoking can greatly reduce your chance of getting AMD. Eating a nutritious diet, including dark leafy green vegetables, may slow the progression of AMD.
A healthy diet and exercise may also help prevent heart disease, high cholesterol, and obesity — all of which can increase the chances of developing AMD.
Regular visits to your primary care doctor and retinal specialist (ophthalmologist) will ensure AMD and any modifiable risk factors are treated or controlled whenever possible.
Dr. Katherine Duncan is an ABMS board certified ophthalmologist specializing in comprehensive ophthalmology, cataract surgery, and oculoplastic surgery. Dr. Duncan completed a fellowship in orbital, oculoplastic, and aesthetic surgery at the University of Pittsburgh Medical Center.